Magnetic coil array



Aug. 28, 1962 H. E. AUSTEN MAGNETIC COIL ARRAY 2 Sheets-Sheet 1 Filed June 12, 1958 FIG. 2

INVENTOR HERMAN E. AUSTEN BY l; ATTORNEY Aug. 28, 1962 H. E. AUSTEN MAGNETIC con ARRAY 2 Sheets-Sheet 2 Filed June 12, 1958 FIG. 7

FIG. 8

INVENTOR HERMAN E. AUSTEN HIS ATTORNEYS United States atent 3,051,930 Patented Aug. 28, 1962 oration of Maryland p Filed June 12, 1958, Ser. No. 741,583

Claims. (Cl. 340-174) This invention relates to an array of helical electric coils invested in solid dielectric material except for axial holes in the coils, and to a process and means for making such an array.

The product made by the process is useful for providing coordinate arrays of coils for controllingbistable magnetic data storage devices used in COIljllIlCtlOIl with said coils. In this instance, the magnetic data storage devices are passed through the holes in the coils and, in addition to storing data magnetically, act as electric conductors for coordinate control with the coils for storing and reading data.

An array, according to this invention, may consist of one or more panels of coils, the coils being spaced therein in rows and columns with the axes of the coils in parallel and perpendicular to the plane of the panel. Where multiple panels of coil arrays are used to form a threedimensional array, panels with the same spacing and pattern of coils are placed in congruence in a stack so the corresponding coils of the panels have their axial holes in alinement making it possible for the associated magnetic storage devices to be passed straight through.

For convenience, the coils of a panel are, in this disclosure, arranged in a square pattern of alined rows and columns, the coils of a row being formed of a continuous electric conductor, by novel means.

The invention provides a process for efiiciently winding and investing in a panel an array of helical electric coils, and to an invested array of coils so made.

The invention further provides such a panel which may be stacked together with other identical panels so the corresponding coils of the arrays have their axial holes in alinement.

Another feature of the invention is the provisiorrof a novel process and means for winding helical coils WlllCh are electrically connected in a series.

With these and incidental objects in view which Wlll become apparent in the description to follow, the invention will be explained with reference to the drawings.

Of the drawings:

FIG. 1 is a perspective of a plate which holds pins on which the coils are wound, said plate also being one of two which together form a mold for casting an investment around the coils, the invested coils forming a panel. A few of the pins are shown in place.

FIG. 2 shows the lefthand portion of a section on the line 22 of FIG. 1, with five winding pins shown in full and showing two coils and part of a third wound.

FIG. 3 is a detail, partly in vertical section, of the first pin of a row, having a coil started thereon by means of the coil-winding device.

FIG. 4 shows the substance of FIG. 3 with the coilwinding device rotated clockwise 90, as viewed from the top.

FIG. 5 is an exploded perspective view of the two plates forming the investment mold, showing the pins for the array of coils, including one wound row, the spacer between the plates, and the bolts for fastening the plates together.

FIG. 6 shows the assembled mold ready for casting the investing material therein.

FIG. 7 is a broken sectional View taken on the line 77 of FIG. 6, only the first three pins and coils being shown.

FIG. 8 is a plan view of a finished panel showing the electric leads common to the coils of a row.

FIG. 9 is a cross section through a stack of panels, partly broken away, showing the top four coils of four panels and their associated magnetic storage devices.

General Description of the Molding Means The invention is adapted for making very compact and small coil arrays in single or multiple panel arrangements, and dimensions of parts of a successful example of the invention will be given, but such dimensions are not in any way to be considered as limiting the scope of the invention.

FIG. 1 shows a plate 20, made of metal or other rigid material, about 2 /2 inches square and of a thickness of /8 of an inch having bored therethrough a square array of pin-receiving holes 21, numbering ten in a row and ten in a column. These holes 21 are spaced 0.1 inch apart in columns and rows, and are 0.015 of an inch in diameter. The pins 22, a full array of which is shown in FIG. 5, are of an inch long, thus projecting A of an inch above the plate 20. A top plate 23 (FIGS. 5, 6 and 7) of the same dimensions, and an array of holes 24 to match holes 21 are provided to form, with spacer 25, a complete mold as shown in FIG. 6, with an opening 26 into which the investing material is poured. Locating pins 27 and 28 in the bottom plate cooperate with holes 29 and 30 in the top plate to aid in assembling the top and bottom plates 20 and 23 and the spacer 25. Bolts 31, 32, 33, and 34 fasten the assemblage of plates and spacer together. The spacer is about of an inch, making a space of the same dimension between plates 20 and 23 for the height of the coils on the pins.

Studs 35, 36, 37, and 38 are provided on the plate 20 to make bolt-receiving holes in the molded panels whereby a number may be fastened in a stack. Studs 39 and 40 are provided in plate 20 to make alining holes for receiving alining rods before the stack of panels is fastened together by bolts.

The Coil Winding Means The coils forming one row of a panel are made of a continuous electrically conductive wire, of 0.005 of an inch in diameter with an electrical insulating coating of about 0.0005 of an inch, making the total diameter of the wire 0.006 of an inch. Ten turns of the wire in a closely wound helical coil is 0.060 of an inch in height which is the clearance between plates 20 and 23 of the molding means.

Referring to FIG. 2, a free end 50 of a wire supply is laid over the edge of plate 20 to form a terminal and from there extends to the first pin 51 of a row, and is wound around pin 51, upwardly, for ten turns and passed onto the next pin 52, by span 53, where it is wound upwardly for ten turns and passed by span 54 to pin 55 which is shown partly wound for the purpose of explaining the method of winding. As shown, the supply end of the wire passes upwardly through a hollow feed tube 56. The supply end 57 of the wire extends to and is delivered from a supply spool, not shown.

The axis of feed tube 56 is parallel to pin 55, and to the other pins with which it cooperates, but is spaced sideways by the forming cylinder 58 attached thereto. The forming cylinder 58 fits over pin 55, or any other pin on which a coil is being wound. Forming cylinder 58 is beveled at the bottom as shown at 59 (see also FIG. 3) and charnfered on the trailing edge 60, to form a coiling foot, as shown in FIG. 4, the cylinder 58 and tube 56 forming a coiling tool. The coiling tool comprising tubes 56 and 58 forms a unit rotatable around the pin over which tube 58 fits. The rotation of the cooling tool unit is in a clockwise direction, as viewed from the top, because the chamfer 60 forms the trailing edge which presses down on the last turn of the coil being formed. If chamfer 60 was on the other side of the bevel, the coiling tool unit would be rotated counter-clockwise around the pin being wound. The bottom of forming tube 58 fits snugly against the pin around which the coil is being Wound, and the bottom of tube 58 rides on top of the last-wound turn. In consequence, the forming tool rides up as the coil is wound so the wire supply is always fed from tube 56 at the proper level and the chamfered portion 60 forces the new turn against the last.

The opening at the bottom end of feed tube 56 is rounded as shown at 61 in FIG. 3 to form an easy passage for the supply end 57 of the wire.

A slight downward pressure of the coiling tool, as it is being rotated by using the upper end of feed tube 56 as a crank, is desirable to form a tight coil.

After ten turns have been made on a pin, the coiling tool is removed, allowing the wire supply 57 to feed through tube 56 so the coil, just made, is not disturbed. The forming tube is then placed over the next pin, the necessary slack in wire 57 being provided and then taken up as the tool is in place on the next pin, leaving but the span 53, 54, etc., between coils.

The coiling is repeated on the pins of a row in sequence, until the last pin is reached. The tool 56, 58 is removed and sufiicient wire is fed out of tube 56 to lay a free end 62 (see FIG. 7) over plate 20, which will extend beyond the mold and therefore be available as an electric terminal just as free end 50 which was described with reference to FIG. 2. The free end 62 is cut to the desired length, which completes the windings of coils in one row.

The other nine rows of pins are similarly wound with coils, the rows each having terminal leads like leads 50 and 62, shown in the various figures of the drawings.

After all the coils of all the rows are wound, the spacer 25 (FIG. 5), which is of U-shape, is set onto plate 20, the opening of U accommodating the pins and coils. The spacer 25 is provided with clearance and positioning holes which cooperate with pins 27 and 28 and bolts 31, 32, 33, and 34. The top plate 23 is set in place by the aid of pins 27 and 28, the portion of the pins 22 which project above the coils entering holes 24. The bolts 31, 32, 33, and 34 are secured in place, forming the mold as it appears in FIG. 6.

The mold of FIG. 6 is set on edge with the opening 26 up and an investment material is poured in to fill the space enclosed by the spacer, thus surrounding the coils. This investment material may be heat-liquifiable wax Which hardens on cooling, a liquid monomer material which may be polymerized to a solid, or equivalent material which may be cast, as long as it is a dielectric.

The investment material is designated as 70 in the various views. The terminal ends of the wire of a row of coils, such as 50 and 62 pass under the spacer and out of the mold by means of clearance slots such as slot 71 (FIG. 5).

The mold then is opened and the completed panel, shown in FIG. 8, is removed. A number of panels may be secured together, as shown in FIG. 9. The locating holes 72 and 73, in the investment material of the panels of a stack, are placed in alinement and rods, such as rod 74, are passed through to aline corresponding coils of the panels so the axial holes of corresponding coils of the panels of a stack are in alinement. The panels of a stack may be bolted together through holes 75, 76, 77, and 78 (FIG. 8) provided therefor and formed in the molding process by studs 35, 36, 37 and 38 (FIG. 1).

It will be apparent that the winding of a coil need not commence on the base plate but at a point thereabove as determined by a shoulder on the winding pin, as shown at 90 in FIG. 2, in which case the coil will be shorter and not reach the surface of the panel formed by the base plate. The foregoing method of making a shorter coil which does not reach one of the surfaces of a panel may be advantageous in physically isolating coils which are end to end in a stack of panels, even though the wire of which the coils are made is electrically insulated.

The alined axial holes of corresponding coils of a stack of panels are served by a bistable magnetic data storage device (FIG. 9) in the form of a wire, or equivalent, passed through the alined coils. The magnetic device 80 preferably is made entirely of magnetic material having a substantially square hysteresis loop so that it may be magnetized to assume one polarity or another and keep such state until a magnetizing force of opposite sense and of SllfilCiGllt value is applied. In another form of magnetic device only a sheath thereof is of magnetic material, the core thereof preferably being of electrically conductive but non-magnetic material, such as a copper wire having an electroplated magnetic sheath. In either instance, the device should be electrically conductive. Current applied to a row of coils and to a selected one of the magnetic devices associated with the row, both currents together constituting the necessary strength to produce magnetic saturation of that selected section of the device associated with said row of coils, and both currents being in a direction aiding such saturation, will cause data to be stored magnetically in the so-selected section of the said device. The data so stored in any section of any device associated with a row of coils may be read and erased by passing a current through the row of coils in the direction and of a strength to produce saturation of the associated areas of the devices associated with the row of coils, in the opposite magnetic polarity, the presence of data being indicated in a magnetic device by an electric impulse being produced therein as the magnetic polarity of a section having data stored therein is reversed in magnetic polarity. The reading of the data automatically erases it because of the change in magnetic polarity of the affected section of a magnetic device.

Resort may be had to twisting such device on its longitudinal axis to make the easy path of magnetization nearly parallel to the circumference thereof in a helical manner. Such expediency is indicated in the publications The Twistor Memory Device published in Bell Laboratories Record of December 1957, pages 488 and 489, and in A New Storage Element Suitable for Large- Sized Memory Arraysthe Twistor, published in the Bell System Technical Journal of November 1957, Volume XXXVI, Number 6, pages 1319 to 1340, inclusive.

The invention is not to be deemed limited to the dimensions of the coil arrays, their configurations, or their component parts, as the invention pertains to processing steps and combinations of parts regardless of dimensions or as to particular materials, as equivalents may be used.

What is claimed is:

1. A unit array of helical electric coils embedded in and supported by a common panel of dielectric material, the coils extending between two plane parallel surfaces of the supporting panel, there being holes in the panel corresponding to the axial holes of the coils, and the coils being arranged in rows and columns with the coils of a row being electrically connected in series with con,- necting terminals extending from the panel edges.

2. A unit array of helical electric coils embedded in and supported by a common panel of dielectric material, said panel having two plane parallel surfaces bounded by edges, the coils being arranged in rows and columns, the coils extending through the panel to the two parallel surfaces, the axial holes of the coils being free of the panel material and at right angles to the parallel surfaces of the panel, and the coils of a row being electrically connected in series by being part of a common wire, the ends of each of said common wires extended beyond the edges of the panel and constituting electric terminals,

the axial holes-in the coils permitting bistable magnetic storage devices to be passed therethrough.

3. A three-dimensional system of helical electric coils consisting of a plurality of unit arrays of helical electric coils, each array of coils being embedded in a panel of dielectric material, each panel having two plane parallel surfaces bounded by edges, the coils of each panel being arranged in rows and columns, the coils of an array extending through the associated panel to the associated two parallel surfaces thereof with the axial holes being at right angles to the parallel surfaces and free of the panel material, the coils of each row in a panel being electrically connected in series by being part of a common wire, the ends of which wires extend beyond the edges of the associated panel and constituting electric terminals, the arrays of coils in the panels having the same dimensions and configurations and the panels being stacked and secured with the axial holes of corresponding coils in the panels being in alinement to permit the passage of a bistable magnetic data storage device through each set of coils in alinement.

4. An array of helical electric coils embedded in a panel of supporting dielectric material having two plane parallel surfaces, the coils having their axes at right angles to the plane surfaces, the axial holes being free of the dielectric material and opening onto a first one of the plane surfaces and each coil having access to the second plane surface of the associated panel through an auxiliary hole associated therewith which hole is made through the panel co-axial with the associated coil axis, whereby a number of panels may be stacked first plane surface of one to the second plane surface of an adjacent panel without the coils of the different panels being in physical contact.

5. A unit array of electrical coils comprising a plurality of helical electrical coils having axial holes, said coils being arranged in such a manner that corresponding ends of the coils lie in the same respective planes with the axes of said holes in a parallel relationship and said coils invested, except for said axial holes, in a solid supporting panel of dielectric material having two plane surfaces corresponding to said planes and a thickness corresponding to the length of said coils.

References Cited in the file of this patent UNITED STATES PATENTS 2,552,999 Pannell et a1 May 15, 1951 2,738,466 Niederman Mar. 13, 1956 2,741,436 Belek Apr. 10, 1956 2,743,507 Kornei May 1, 1956 2,758,797 Miklau Aug. 14, 1956 2,784,391 Rajchman et a1. Mar. 5, 1957 2,786,187 Nims Mar. 19, 1957 2,824,294 Saltz Feb. 18, 1958 2,829,426 Franklin Apr. 8, 1958 

